Fix deadlocking on Linux clipboard test (2)

internal/driver/glfw/window.go

@@ -203,17 +203,13 @@ func (w *window) Close() {
 
 	// trigger callbacks - early so window still exists
 	if w.onClosed != nil {
-		w.QueueEvent(w.onClosed)
+		w.onClosed()
 	}
 
-	// set w.closing flag inside draw thread to ensure we can free textures
-	runOnMainWithContext(w, func() {
-		w.closing = true
-		w.viewport.SetShouldClose(true)
-
-		cache.RangeTexturesFor(w.canvas, w.canvas.Painter().Free)
-	})
+	w.closing = true
+	w.viewport.SetShouldClose(true)
 
+	cache.RangeTexturesFor(w.canvas, w.canvas.Painter().Free)
 	w.canvas.WalkTrees(nil, func(node *common.RenderCacheNode, _ fyne.Position) {
 		if wid, ok := node.Obj().(fyne.Widget); ok {
 			cache.DestroyRenderer(wid)

internal/driver/glfw/window_test.go

@@ -1668,7 +1668,7 @@ func TestWindow_CloseInterception(t *testing.T) {
 		w.SetCloseIntercept(func() { onIntercepted = true })
 		w.SetOnClosed(func() { onClosed = true })
 		w.Close()
-		w.WaitForEvents()
+
 		assert.False(t, onIntercepted, "the interceptor should not have been called")
 		assert.True(t, onClosed, "the on closed handler should have been called")
 		assert.True(t, w.viewport.ShouldClose()) // For #2694